There's a small hole in the wall Chinese Restuarant where I used to go for food that was pretty close to Chinatown. They have your usual lunch specials but their roast meats (chicken or pork) aren't that bad either and they also have seasonal specials. It's called Hing Won and it's on 48th St between 5th and 6th avenue, lunch will probably run you about $6.

hing won is far and away the best interesting cheap lunch option -- along w/ indus express (indian) on the same block. i am always baffled when co-workers choose, day after day, to pay two bucks more for a sandwich of facttory made turkey product on a factory made roll (with iceberg)

how do you define cheap? In the $6 range, there's Yip's for mostly low-grade Chinese food. i do like their low brow version of beef curry stew, though. (there are chunks of fatty meat that many gringos disdain, but that i like.)

indus express is indeed great (esp. for chaat, if you eat lighter lunches; $4 or $5 a pop).

there are lots of chicken rice carts that give you a heaping container of gyro over rice for $5 or $6.

there's a tiny, slightly grungy sandwich / hot bar / salad bar place one door west of the duane read that's just south of rock center. (sorry, i know, crap directions; i'll try to pay attn to which st. it's on and what the place is called next time.) they have a passable salad bar with your choice of 8 toppings.